Silence, and then emptiness as the Doctor disappeared from his head. The Master just sat there blankly for a long minute, exhausted beyond thought, just... sitting. Recovering enough to wrench himself back into the real world.
He opened his eyes, and saw the Doctor - and was on his knees beside him before conscious thought could be formed. His fingers fumbled for a pulse, clumsy with exhaustion, even as he saw the Doctor's chest move; he was still breathing. He cupped a hand round the Doctor's cheek, staring into those wide, vacant eyes, hearts pounding with fear. "Doctor?" he whispered, voice rough and weak.